Field of the Invention
The present invention relates to an ion-exchanger for removing impurity ion from a cooling liquid in a fuel cell system.
Related Art
In a fuel cell system of a conventional technology, a cooling circuit is provided for forcibly circulating a cooling liquid (coolant) by means of a pump to cool a fuel cell that generates heat in accordance with power generation. In such cooling circuit, the cooling liquid circulates, and if rust or like is produced, impurity ion is generated in the cooling liquid.
It has been known that such impurity ion increases electric conductivity, which results in that electricity generated by a fuel cell leaks externally through the cooling liquid, and hence, a power generation efficiency is lowered, thus providing a problem. In order to solve such problem, an ion-exchanger for removing the impurity ion in the cooling liquid is provided for the cooling circuit of the fuel cell system.
An ion-exchange resin is packed in such ion-exchanger, and an impurity ion is removed from the cooling liquid by passing the cooling liquid through the ion-exchange resin.
It is further to be noted that ion-exchanging capability of the ion-exchange resin is degraded by repeated use for removing the impurity ion, so that it is necessary to periodically exchange the ion-exchange resin.
According to the such reason as mentioned above, it has been known that an invention disclosed in Patent Document 1 (Japanese Patent Laid-open No. 2005-149842) has provided a cartridge-type ion-exchanger capable of discharging water in the cooling circuit so as not to leak from the ion-exchanger during exchanging of a filter cartridge and performing an exchanging working without closing pipes or ducts disposed at for-and-aft positions of the ion-exchanger.
The Patent Document 1 discloses a cooling device including a cooling circuit, for circulating a cooling liquid, formed between a fuel cell stuck and a radiator, and an ion-exchanger for removing ion from a cooling liquid is disposed in the cooling circuit. The ion-exchanger is composed of an exchangeable filter cartridge, a container body in which the filter cartridge is accommodated, and a lid member for closing an opening of the container body through which the filter cartridge is exchanged.
The ion-exchanger of the structure mentioned above is located in a manner such that the opening of the container body is positioned above the highest liquid level in the cooling circuit.
According to the ion-exchanger disclosed in the above Patent Document 1, since the ion-exchanger is located in a manner such that the opening of the container body is positioned above the highest liquid level in the cooling circuit, the filter cartridge can be exchanged with the cooling liquid being kept in the container without discharging the cooling liquid and closing pipes disposed for-and-aft of a filter during the exchanging of the filter cartridge, thereby easily performing the exchanging working.
However, in the structure of the ion-exchanger of the Patent Document 1, since the cooling liquid discharging opening is formed to the lid member, when the lid member is removed at the same time of exchanging the filter cartridge, there is a fear of back-flow of the cooling liquid through the discharge opening, and also, when the filter cartridge is exchanged, it is necessary to remove the lid member, which makes complicated the exchanging working, thus also providing inconvenience.